CN113728173B

CN113728173B - Gear shift group and drive train having a gear shift group of this type

Info

Publication number: CN113728173B
Application number: CN202080030679.2A
Authority: CN
Inventors: 约亨·洛菲尔曼; 西蒙·勒布纳; 瓦尔德马·诺伊格鲍尔
Original assignee: Schaeffler Technologies AG and Co KG
Current assignee: Schaeffler Technologies AG and Co KG
Priority date: 2019-04-23
Filing date: 2020-04-02
Publication date: 2023-09-05
Anticipated expiration: 2040-04-02
Also published as: US20220196080A1; US11808305B2; CN113728173A; DE102019110478A1; WO2020216406A1

Abstract

The application relates to a shift group (1) for a drive train of a motor vehicle for coupling and uncoupling drive shafts (14, 15) of the drive train as required, having an actuator (2) for actuating a blocking element (6), a selector lever (8) and a selector fork (9) connected to the selector lever (8), wherein the first drive shaft (14) and the second drive shaft (15) are coaxially arranged with respect to each other, wherein the blocking element (6) blocks an axial displacement of the selector lever (8) in a first switching position and enables said axial displacement in a second switching position, wherein the selector fork (9) is engaged into a recess (19) of one of the drive shafts (14, 15), wherein actuation of the shift group (1) causes an axial displacement of the drive shafts (14, 15), wherein a clutch (50) between the first drive shaft (14) and the second drive shaft (15) is opened or closed by means of the axial displacement of the selector fork (9).

Description

Gear shift group and drive train having a gear shift group of this type

Technical Field

The present application relates to a shift group for coupling and uncoupling a shaft to a drive train of a motor vehicle and a drive train having such a shift group according to the preamble of the independent claims.

Background

In motor vehicles with switchable all-wheel drives, so-called "disconnection systems" for decoupling components of the drive train are known. In the context of increasingly electrified motor vehicles, hybrid drives are known in which the main drive is provided by an internal combustion engine or a first electric motor which drives the wheels on the main drive shaft of the motor vehicle. It is also known to drive the wheels of the second axle by means of a further electric motor, which can be coupled to the drive train by means of a switchable axle drive. The following hybrid vehicles are known from the prior art: the hybrid vehicle has an electric drive motor and an internal combustion engine operatively connected in a common driveline. The following hybrid vehicles are known: in the hybrid vehicle, the electric motor may be turned on to increase the driving torque when the internal combustion engine is at a low speed. In particular, such a hybrid drive may be used to represent a switchable all-wheel drive for a motor vehicle, wherein the internal combustion engine and the electric motor act on different drive shafts. Furthermore, in order to recover energy during braking, the electric motor may be switched on for retraction purposes. The hybrid drive concept with different drive machines allows for a variable drive concept that can be easily adapted to the respective operating conditions by switching the various motors on and off as required. If necessary, it may be necessary to separate one or more drive motors from the drive train of the motor vehicle in order to minimize losses in the drive train and/or to avoid damaging the drive motors due to operation outside the allowed operating range, in particular outside the allowed maximum speed.

Alternatively, such a shift group can also be used in motor vehicles with hybrid drive to separate the transmission from the drive train in the operating state driven by the electric motor alone, in order to reduce power losses and to minimize transmission noise.

DE 10 2014 217 066 A1 discloses a clutch for switchable all-wheel drive, in which two coaxial drive shafts are connected to one another by means of a clutch element which enables a positive connection between the two drive shafts. The clutch has a shift element with which a clutch part that can be displaced in the axial direction is displaced in such a way that a positive-locking connection between the two drive shafts is established.

A coupling assembly for a drive train of a motor vehicle is known from WO 2011/098 595a1, which coupling assembly comprises at least one clutch arranged on a rotating shaft for selectively coupling the rotating shaft to a drive element of the drive train. The coupling assembly further comprises at least one actuation means for actuating the clutch. The actuation means is designed to selectively engage the engagement section with the threaded section rotating with the shaft to cause a relative movement of the engagement section and the threaded section along the axis of the rotating shaft and thereby actuate the clutch in the axial direction.

Disclosure of Invention

The object of the application is to create a particularly simple, lightweight and low-cost gear shift group that enables the drive train to be coupled and uncoupled as required.

The proposed design and arrangement of the mechanical device makes it possible in particular to design the drive train and/or the shift set as separate components which can be integrated into the existing drive shaft due to their modular construction.

According to the application, this object is achieved by a shift group for a drive train of a motor vehicle for coupling and uncoupling a drive shaft of the drive train as required, comprising an actuator for actuating a blocking element, a selector lever and a selector fork connected to the selector lever, wherein the first drive shaft and the second drive shaft are coaxially arranged with respect to each other. The blocking element prevents axial displacement of the selector lever in the first shift position and releases the axial displacement in the second shift position. It is provided that the selector fork engages into a recess in one of the drive shafts, wherein actuation of the shift group causes an axial displacement of the drive shafts. By axially displacing the selector fork, the clutch between the first and second drive shafts is opened or closed, such that in a first operating state, drive torque is transferred from the first drive shaft to the second drive shaft, and in a second operating state, the connection between the first and second drive shafts is interrupted. The actuator preferably has a linearly displaceable actuator pin, which is operatively connected to the blocking element when the actuator pin is extended, makes it possible to actuate the shift group particularly simply. The gear shifting mechanism can be unlocked in a simple manner and displaced in the axial direction in order to terminate the connection between the first drive shaft and the second drive shaft, via which connection a torque can be transmitted. In this way, the drive motor, in particular the electric drive motor, can be switched on in order to increase the drive torque and to increase the efficiency of the motor vehicle, in particular during starting and acceleration. The actuator may be designed as an electrically or hydraulically operated actuator, wherein actuation of the actuator, in particular application of a voltage to the actuator, results in actuation of the actuator. This ensures that the switchable drive motor is decoupled in case of a failure of the actuator. Alternatively, the side shaft of the drive train may be uncoupled by an actuator to minimize friction losses. It is provided in particular that the second drive motor and/or the transmission is decoupled from the drive train by means of an actuator, so that the transmission is decoupled from the drive train and thus the power loss is minimized when the load demand is low.

In a preferred embodiment of the application, it is provided that the actuator comprises a lifting magnet. The lifting magnet makes it possible to actuate the actuator pin particularly simply. Thus, the blocking element can be actuated in a particularly simple manner, thereby facilitating the coupling or uncoupling of the drive shaft.

In a preferred embodiment of the application, it is provided that the blocking element has a blocking pawl which, in the first shift position, rests in a recess of the selector lever and thus blocks an axial displacement of the selector lever, and, in the second shift position, blocks a unscrewing of the pawl from the recess so that the selector lever can be displaced axially. The axial displacement of the selector shaft can be blocked in a simple manner by means of a blocking pawl. The blocking pawl may release or lock the axial displacement of the selector rod by rotating the blocking element. Alternatively, a blocking pawl may also be engaged in a recess in the selector rod to block axial displacement.

In an advantageous embodiment of the shift group, it is provided that the selector lever is pretensioned in the axial direction by means of a compression spring. The compression spring allows the selector lever and the selector fork connected thereto to be moved in a simple and cost-effective manner so as to enable the drive shaft to be coupled or uncoupled. The compression spring urges the switching mechanism in the direction of the drive shaft clutch to establish a positive and/or non-positive connection between the first drive shaft and the second drive shaft so that torque can be transferred via the drive shaft clutch.

In a preferred embodiment of the application, it is provided that a control pin is received in the selector lever, which control pin protrudes in the radial direction on the selector lever. The control pin can be used to easily push the switch lever back into the starting position. This can be done by means of a correspondingly designed mechanism or additional actuators. The preferred embodiment is to effect the pushing back of the selector lever to decouple the second drive shaft by means of a suitable mechanism so that the shift set is managed using only one actuator.

It is particularly preferred that a control profile is formed on one of the drive shafts, which control profile can be operatively connected with the control pin and thereby displace the selector rod in the axial direction. The control profile is designed in particular as a cam or an inclined profile. The control pin is actuated via the control profile in such a way that: i.e. the selector rod is pushed back into the starting position of the selector rod against the force of the compression spring. The connection between the first drive shaft and the second drive shaft is thus released. If the selector rod is displaced far enough in the axial direction against the force of the compression spring, the blocking pawl can be reset by rotating the locking element. Thus, the blocking element blocks the axial movement of the displacement unit by blocking the pawl. Once the selector rod has been axially displaced, no lateral load is applied to the control pin and the pin spring returns the control pin to its original position. The selector lever is pretensioned by a compression spring and pressed against the blocking pawl.

In an advantageous development of the application, it is provided that the shift group has a torsion spring which is operatively connected to the blocking element such that, when the actuator is not actuated, the torsion spring rotates the blocking element back into the initial position of the blocking element. By means of the torsion spring, a restoring force can be generated in a simple and cost-effective manner, which restoring force restores the blocking element to its starting position against the rotation of the actuator. This ensures that the pawl engages in a reliable manner so that axial displacement of the selector lever is avoided in case of failure of the actuator.

In a preferred embodiment of the shift group, it is provided that the first drive shaft and the second drive shaft can be connected to each other by means of a claw clutch. By means of the dog clutch, torque can be transmitted between two coaxial drive shafts in a simple and reliable manner. This enables the second drive shaft to be connected to the drive train in a simple manner.

Alternatively, it is advantageously provided that a synchronization mechanism is arranged between the first drive shaft and the second drive shaft in order to equalize the speeds of the drive shafts. The synchronization mechanism enables the second drive shaft to be coupled to the first drive shaft in a particularly convenient manner. In addition, shift shocks, which may reduce the durability of the clutch, may be avoided or reduced.

In an advantageous embodiment of the application, it is provided that the stop for the selector lever is damped using a plastic disk to optimize the acoustic effect of the drive train. The acoustic damping may be implemented by means of a suitable plastic disc, wherein the selector rod is capable of being uncoupled from the housing or carrier in which the selector rod is mounted. This minimizes the transmission of noise generated by the structure, thereby reducing the generation of noise.

In an advantageous embodiment of the shift mechanism, it is provided that the selector fork and the actuator are arranged in a common housing. The common housing is capable of acoustic packaging, which may reduce noise. Furthermore, with the aid of such a housing, the risk of malfunctions due to dirt or dust entering the gear shift group can be minimized.

In a further development of the shift mechanism, it is provided that the shift group comprises electronics, in particular sensors, with which the coupling state of the drive train can be determined. The electronic device may in particular have a position sensor for detecting the position of the selector lever. This enables checking whether the clutch is open or closed. Furthermore, when the sensor detects that the drive train is in an operating state in which no coupling or decoupling for component protection should be performed, the shift command may be prevented from being forwarded to the actuator.

According to the application, a drive train with a first drive shaft and a second drive shaft is proposed. The drive shafts of the drive train can be connected to each other via a switchable clutch by means of a gear shift group according to the application. By means of such a drive train, the additional drive motor can be switched on or off in a simple manner. The speed between the two drive shafts of the drive train can be regulated by means of a synchronizing mechanism in order to ensure a comfortable connection of the switchable drive motor and to avoid gear shifting shocks which would reduce the service life of the drive motor and/or of the motor vehicle transmission and which would be regarded as disturbing in terms of comfort by passengers of a motor vehicle with such a motor vehicle transmission.

The various embodiments of the application recited in this application can be advantageously combined unless otherwise specified in the individual cases.

Drawings

Hereinafter, the present application will be described by means of preferred embodiments with reference to the accompanying drawings. Identical components or components having identical functions are identified by identical reference numerals. In the drawings:

fig. 1 shows an exemplary embodiment of a drive train with a shift set according to the application in a three-dimensional schematic representation;

fig. 2 shows a side view of a drive train with a gear shift set according to the application; and

fig. 3 shows a further schematic representation of a drive train with a gear shift group according to the application.

Detailed Description

In fig. 1, an exemplary embodiment of a drive train of a motor vehicle is shown with a switchable side train. Such a drive train can be used in particular for motor vehicles with switchable all-wheel drive or with a plurality of drive motors which drive different drive axles of the motor vehicle. The drive train comprises a first drive shaft 14 and a second drive shaft 15, which can be connected to each other in a rotationally fixed manner by means of a switchable drive shaft clutch 50, in particular by means of a switchable claw clutch 16. The two drive shafts 14, 15 have contours, in particular teeth, on their end faces 17, 18 facing one another, via which a positive fit can be established between the first drive shaft 14 and the second drive shaft 15. The first drive shaft 14 has a toothing 26 at its end facing away from the drive shaft clutch 50, on which toothing 26 the first drive shaft can be connected in a non-rotatable manner to a drive unit, in particular an electric drive motor or a gearbox, in order to transmit torque. The second drive shaft 15 has a toothing 27 at its end facing the drive shaft clutch 50, with which toothing the second drive shaft 15 can be connected in a non-rotatable manner to a second drive motor or gear, in particular an axle drive or differential.

The drive shaft clutch 50 can be opened and closed by means of the shift group 1. The gear shift group 1 comprises an actuator 2, which is preferably designed as an electric actuator 4, in particular as a lifting magnet 24. Alternatively, the actuator 2 may also be designed as a hydraulic actuator 3. The actuator 2 has an actuator pin 5 which is capable of linear displacement when the actuator 2 is activated and acts on a blocking element 6 which rotates when the actuator 2 is activated. The shift group 1 further comprises a shift mechanism 8, 9 having a selector rod 8 and a selector fork 9 firmly connected to the selector rod 8. The selector fork 9 is connected to the selector rod 8 by means of a connecting element 10. The selector fork 9 engages into a recess 19 or shoulder in the first drive shaft 14, whereby a form-fitting connection is formed between the selector fork 9 and the first drive shaft 14. The selector rod 8 is pretensioned by means of the compression spring 11 and fixed in its starting position by the blocking pawl 20, wherein the blocking pawl 20 engages into a groove 21 or shoulder of the selector rod 8 and thus fixes the selector rod 8 in its position. The blocking pawl 20 can be opened by means of the blocking element 6. For this purpose, the blocking element 6 is rotated by the actuator pin 5 against the force of the torsion spring 12 and thus lifts the blocking pawl 20 out of the recess 21 or shoulder of the selector rod 8.

The control pin 7 is received in the selector rod 8 and protrudes in a radial direction on the selector rod 8. The control pin 7 is pretensioned by a pin spring 13. A control contour, in particular an inclined contour 23 or a cam 25, which can be operatively connected to the control pin 7, is formed on the second drive shaft 15. If the activation of the actuator 2 is ended and the actuator pin 5 is retracted again, the torsion spring 12 returns the blocking element 6 to its starting position. The control pin 7 will push the selector rod 8 against the spring force of the compression spring 11 back to its initial position until the blocking pawl 20 again engages into the groove 21 or shoulder of the selector rod 8 and locks the selector rod in the axial direction. The shift group 1 further comprises a sensor 22, in particular a position sensor, in order to monitor the shift position and to determine whether the two drive shafts 14, 15 are in the coupled or uncoupled operating state. The gear shift set 1 may also comprise other electrical components and/or sensors in order to facilitate actuation and/or to facilitate checking functions.

In fig. 2, an embodiment of a shift group 1 according to the application is shown for switching a drive motor in a drive train of a motor vehicle on and off on demand. The shift group 1 comprises an actuator 2, in particular an electrically actuatable actuator 4, which when the actuator 2 is activated results in a linear displacement of an actuator pin 5. When the actuator 2 is activated, the actuator pin 5 is in operative connection with a blocking element 6, which rotates during the linear displacement of the actuator pin 5, so that the axial displacement of the switching mechanism 8, 9 of the shift group 1 is released. The gear shifting mechanism 8, 9 comprises a selector rod 8 and a selector fork 9, which is connected to the selector rod 8 by means of a connecting element 10. The selector rod 8 is pretensioned by the compression spring 11 such that when the shift mechanism 8, 9 is released by rotating the blocking element 6, release of the blocking pawl 20 results in axial displacement of the selector rod 8 and thus of the selector fork 9. For this purpose, the selector fork 9 engages in a recess 19 in the first drive shaft 14, so that a positive-locking connection is formed between the selector fork 9 and the first drive shaft 14.

The selector lever 8 carries a control pin 7 which protrudes in a radial direction on the selector lever 8. The control pin 7 can be operatively connected to a control contour 23, in particular an inclined contour or cam 25 on the second drive shaft 15, wherein the control pin 7 is preferably received in a form-fitting manner in the control contour 24 and is latched into the latter. The shift group 1 further comprises a torsion spring 12 which, upon activation, in particular upon termination of the energization, of the actuator 2 rotates the blocking element 6 against the movement of the actuator 2 back into its starting position.

In fig. 3, the drive train is shown with further improvement. The gear shift group 1 is provided in particular to separate the drive motors and/or the transmission from the drive train in a motor vehicle with two drive motors, and thus to minimize friction and power losses when only low power demands are present in the motor vehicle, which can be met by one of the drive motors. In fig. 1 to 3, the drive shaft clutch 50 is shown in an open operating state in which the actuator 2 is not activated and thus the two drive shafts 14, 15 are separated from each other, so that no drive torque is transmitted between the first drive shaft 14 and the second drive shaft 15. By activating the actuator 2, the blocking element 6 rotates, thus the blocking pawl 20 lifts out of the recess 21 of the selector lever 8. The selector rod 8, which is pretensioned by the spring force of the compression spring 11, is thus displaced in the axial direction, so that the two mutually facing end surfaces 17, 18 of the drive shafts 14, 15 are pressed against each other and the drive shaft clutch 50 is closed. Thus, the second drive shaft 15 is coupled to the first drive shaft 14.

List of reference numerals

1 gear shift group

2 actuator

3 Hydraulic actuator

4 electric actuator

5 actuator pin

6 Barrier element

7 control pin

8 selector lever

9 selector fork

10 connecting element

11 compression spring

12 torsion spring

13 pin spring

14 first drive shaft

15 second drive shaft

16 claw clutch

17 first side

18 second side

19 grooves

20 blocking pawl

21 groove

22 sensor

23 oblique profile

24 lifting magnet

25 cam

26 tooth portions

27 tooth parts

50 drive shaft clutch.

Claims

1. A gear shift group (1) for a drive train of a motor vehicle for coupling and uncoupling a drive shaft (14, 15) of the drive train as required, comprising:

an actuator (2) for actuating the blocking element (6),

-a selector rod (8) and a selector fork (9) connected to the selector rod (8), wherein

The first drive shaft (14) and the second drive shaft (15) are coaxially arranged with respect to each other,

the blocking element (6) blocks an axial displacement of the selector lever (8) in a first shift position and releases the selector lever in a second shift position,

it is characterized in that the method comprises the steps of,

-engagement of the selector fork (9) into a recess (19) of one of the drive shafts (14, 15), wherein actuation of the shift group (1) causes an axial displacement of the drive shaft (14, 15), wherein

-the clutch (50) between the first drive shaft (14) and the second drive shaft (15) is opened or closed by means of an axial displacement of the selector fork (9) such that

-in a first operating condition, drive torque is transmitted from the first drive shaft (14) to the second drive shaft (15), and

-in a second operating condition, the connection between the first drive shaft (14) and the second drive shaft (15) is interrupted;

the blocking element (6) has a blocking pawl (20) which in the first shift position rests in a recess (21) of the selector lever (8) and thus blocks an axial displacement of the selector lever (8), and in the second shift position the blocking pawl (20) is rotated out of the recess (21) so that the selector lever (8) can be displaced axially.

2. Gear shift group (1) according to claim 1, characterized in that the actuator (2) comprises a lifting magnet (24).

3. Shift group (1) according to claim 1 or 2, characterized in that the selector rod (8) is pretensioned in the axial direction by means of a compression spring (11).

4. Shift group (1) according to claim 1 or 2, characterized in that the selector lever (8) has received therein a control pin (7) protruding in a radial direction on the selector lever (8).

5. A gear shift group (1) according to claim 4, characterized in that a control profile (23, 25) is formed on one of the drive shafts (14, 15), which control profile is operatively connectable with the control pin (7) and thereby displaces the selector lever (8) in the axial direction.

6. A gear shift set (1) according to any one of claims 1,2 or 5, characterized in that the gear shift set (1) has a torsion spring (12) operatively connected with the blocking element (6) such that the torsion spring (12) rotates the blocking element (6) back to its initial position when the actuator (2) is not actuated.

7. The gear shift group (1) according to one of claims 1,2 or 5, characterized in that the first drive shaft (14) and the second drive shaft (15) are connectable to each other by means of a claw clutch (16).

8. A gear shift group (1) according to any one of claims 1,2 or 5, characterized in that a synchronizing mechanism is arranged between the first drive shaft (14) and the second drive shaft (15) in order to equalize the speeds of the drive shafts (14, 15).

9. A transmission line with a first drive shaft (14) connectable to a first drive motor or a transmission and with a second drive shaft (15) connectable to a second drive motor, the first drive shaft (14) and the second drive shaft (15) being connectable to each other and to a shift group (1) according to any one of claims 1 to 8 via a drive shaft clutch (50).